Within the technical field of microwave frequency connectors there exist male contact pins designed to solder onto printed circuit boards (PCBs). These contact pins are metallic and are generally surrounded by a plastic insulator and a metallic housing providing a connector pin assembly. The connector pin assemblies can be coupled by various methods including a push-on design. The contact pins are a key component in the transmission of the electrical signal. There are instances where, due to tolerance stack and PCBs that are not flat, the connector needs to overcome large variable distances and still maintain good performance at high frequencies. Accordingly, efforts have been focused on developing connector pin assemblies incorporating so-called “floating” contact pins, which axially move bidirectionally to accommodate the non-uniformity of a PCB's surface flatness. However, the axial movement of the contact pins has to be restrained in both directions to allow the contact pin to be retained in the carrier or header; and to work, the restraints must be diametrically larger than the inside diameter of a passage in the carrier or header. The difficulty in assembly of the connector pin assembly involves inserting a contact pin with two restraints through a passage when the restraints are larger than the passage, and doing so without damaging the carrier or header. This is especially difficult with connector pin assemblies incorporating multiple contact pins.
Referring to FIGS. 1 and 2, a conventional floating pin assembly 100 is illustrated. A single pin arrangement is shown in FIG. 1, and a multi-pin arrangement is shown in FIG. 2. In FIGS. 1 and 2, each pin 102 is shown installed through a hole 104 in a carrier 106. The pin 102 is typically manufactured of an electrically conductive material, for example a metal, while the carrier 106 is typically manufactured of a dielectric material such that the carrier 106 may act as an insulator to the pin 102. The carrier 106 may also be referred to as a header. To allow the pin 102 to “float”, the pin 102 has a shaft 108 with a smaller outside diameter than an inside diameter of the hole 104. In this way, the shaft 108 may freely slide in the hole 104, thereby allowing the pin 102 to axially move. However, it is necessary to limit the amount of bidirectional axial movement of the pin 102 to maintain the pin 102 within the carrier 106. To provide such bidirectional limitation, the pin 102 has two integral restraints, a first restraint 110, to limit the axial movement of the pin 102 in a first direction, and a second restraint 112 to limit the axial movement of the pin 102 in a second direction.
The first restraint 110 and the second restraint 112 extend radially outwardly from the surface of the shaft 108. However, to be able to limit the axial movement of the pin 102, both the first restraint 110 and the second restraint 112 must extend radially outwardly from the shaft 108 to a circumferential periphery beyond the outside diameter of the hole 104. Typically, both the first restraint 110 and the second restraint 112 are formed monolithically with and as part of the pin 102. Because of the requisite size and the monolithic construction of the pin 102, one of the first restraint 110 or second restraint 112 must be inserted in the carrier 106 by forcing it through the hole 104 during assembly of the floating pin assembly 100. Accordingly, one or both of the first restraint 110 and second restraint 112 may have a rounded or angled edge or surface to facilitate such insertion. As can be seen in FIGS. 1 and 2, the first restraint 110 has an angled surface 114, indicating that the pin 102 was inserted in the carrier 106 by forcing the first restraint 110 through the hole 104. While the angled surface 114 may facilitate installation of the pin 102 to a certain extent, such installation puts stress on the material of the carrier 106, which may result in cracks or some other structural impairment physically compromising the carrier 106 and/or compromising its insulating integrity. Additionally, the angled surface 114 allows the pin 102 to be installed in one direction only.
The chance of such structural impact and the compromising effects are compounded with multi-pin arrangements as illustrated in FIG. 2. Five pins 102 are shown in FIG. 2, and each may have been installed by forcing the respective first restraint 110 through the respective hole 104 in the carrier 106. Although the pin 102 may axially move bidirectionally in the hole 104, such movement only occurs between the first restraint 110 and the second restraint 112. As such, once installed, the pin 102 may not be removed either by continuing to force the pin 102 in the same direction as installed, or by forcing it back through the hole 104. Accordingly, once one of the pins 102 is installed in the carrier 106, it cannot be removed without damaging the carrier 106.
In FIG. 2, the second restraints 112 are shown engaging with a printed circuit board (PCB) 116. In this regard, the second restraint 112 on each pin 102 is also used as a contact head to be connected to the PCB 116, and may be soldered to a conductive trace (not shown in FIG. 2) on the PCB 116. The PCB 116 may not be perfectly flat or planar but may have surface non-uniformities, such as, for example, a bow, as is illustrated in FIG. 2 with regard to the PCB 116. As the different second restraints 112 engage the PCB 116, the non-uniformity in the surface of the PCB 116 causes the second restraints 112 to move, which axially moves the pins 102, allowing the pins 102 to “float”. However, because the second restraints 112 are also used as contact heads, the non-uniformity of the PCB 116 may cause the second restraints 112 to be forced against the carrier 106. This is shown in FIG. 2 by the pin 102 installed in the middle. Not only may this installation add to the possibility of damage to the carrier 106, but it may also compromise the integrity of the connection of the second restraint 112 to the conductive trace on the PCB 116.
Consequently, there is an unresolved need for a radio frequency (RF) connector pin assembly that not only provides a pin that moves axially, or floats, to accommodate the non-uniformity of a PCB surface, but can also be installed without compromising a carrier or header, or the connection to the PCB.
No admission is made that any reference cited herein constitutes prior art. Applicant expressly reserves the right to challenge the accuracy and pertinence of any cited documents.